core 2.0 - best way to impersonate a Windows user?

Question

With .NET web apps, I am able to impersonate a Windows user easily enough using this class:

/// <summary>
///  TOOLS IMPERSONATION
/// </summary>
namespace Tools
{
    #region Using directives.
    // ----------------------------------------------------------------------

    using System;
    using System.Security.Principal;
    using System.Runtime.InteropServices;
    using System.ComponentModel;

    // ----------------------------------------------------------------------
    #endregion

    /////////////////////////////////////////////////////////////////////////

    /// <summary>
    /// Impersonation of a user. Allows to execute code under another
    /// user context.
    /// Please note that the account that instantiates the Impersonator class
    /// needs to have the 'Act as part of operating system' privilege set.
    /// </summary>
    /// <remarks>   
    /// This class is based on the information in the Microsoft knowledge base
    /// article http://support.microsoft.com/default.aspx?scid=kb;en-us;Q306158
    /// 
    /// Encapsulate an instance into a using-directive like e.g.:
    /// 
    ///     ...
    ///     using ( new Impersonator( "myUsername", "myDomainname", "myPassword" ) )
    ///     {
    ///         ...
    ///         [code that executes under the new context]
    ///         ...
    ///     }
    ///     ...
    /// 
    /// Please contact the author Uwe Keim (mailto:[email protected])
    /// for questions regarding this class.
    /// </remarks>
    public class Impersonator :
        IDisposable
    {
        #region Public methods.
        // ------------------------------------------------------------------

        /// <summary>
        /// Constructor. Starts the impersonation with the given credentials.
        /// Please note that the account that instantiates the Impersonator class
        /// needs to have the 'Act as part of operating system' privilege set.
        /// </summary>
        /// <param name="userName">The name of the user to act as.</param>
        /// <param name="domainName">The domain name of the user to act as.</param>
        /// <param name="password">The password of the user to act as.</param>
        public Impersonator(
            string userName,
            string domainName,
            string password)
        {
            ImpersonateValidUser(userName, domainName, password);
        }

        // ------------------------------------------------------------------
        #endregion

        #region IDisposable member.
        // ------------------------------------------------------------------

        public void Dispose()
        {
            UndoImpersonation();
        }

        // ------------------------------------------------------------------
        #endregion

        #region P/Invoke.
        // ------------------------------------------------------------------

        [DllImport("advapi32.dll", SetLastError = true)]
        private static extern int LogonUser(
            string lpszUserName,
            string lpszDomain,
            string lpszPassword,
            int dwLogonType,
            int dwLogonProvider,
            ref IntPtr phToken);

        [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern int DuplicateToken(
            IntPtr hToken,
            int impersonationLevel,
            ref IntPtr hNewToken);

        [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        private static extern bool RevertToSelf();

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        private static extern bool CloseHandle(
            IntPtr handle);

        private const int LOGON32_LOGON_INTERACTIVE = 2;
        private const int LOGON32_PROVIDER_DEFAULT = 0;

        // ------------------------------------------------------------------
        #endregion

        #region Private member.
        // ------------------------------------------------------------------

        /// <summary>
        /// Does the actual impersonation.
        /// </summary>
        /// <param name="userName">The name of the user to act as.</param>
        /// <param name="domainName">The domain name of the user to act as.</param>
        /// <param name="password">The password of the user to act as.</param>
        private void ImpersonateValidUser(
            string userName,
            string domain,
            string password)
        {
            WindowsIdentity tempWindowsIdentity = null;
            IntPtr token = IntPtr.Zero;
            IntPtr tokenDuplicate = IntPtr.Zero;

            try
            {
                if (RevertToSelf())
                {
                    if (LogonUser(
                        userName,
                        domain,
                        password,
                        LOGON32_LOGON_INTERACTIVE,
                        LOGON32_PROVIDER_DEFAULT,
                        ref token) != 0)
                    {
                        if (DuplicateToken(token, 2, ref tokenDuplicate) != 0)
                        {
                            tempWindowsIdentity = new WindowsIdentity(tokenDuplicate);
                            impersonationContext = tempWindowsIdentity.Impersonate();
                        }
                        else
                        {
                            throw new Win32Exception(Marshal.GetLastWin32Error());
                        }
                    }
                    else
                    {
                        throw new Win32Exception(Marshal.GetLastWin32Error());
                    }
                }
                else
                {
                    throw new Win32Exception(Marshal.GetLastWin32Error());
                }
            }
            finally
            {
                if (token != IntPtr.Zero)
                {
                    CloseHandle(token);
                }
                if (tokenDuplicate != IntPtr.Zero)
                {
                    CloseHandle(tokenDuplicate);
                }
            }
        }

        /// <summary>
        /// Reverts the impersonation.
        /// </summary>
        private void UndoImpersonation()
        {
            if (impersonationContext != null)
            {
                impersonationContext.Undo();
            }
        }

        private WindowsImpersonationContext impersonationContext = null;

        // ------------------------------------------------------------------
        #endregion
    }

    /////////////////////////////////////////////////////////////////////////
}

However, I cannot use this with asp net core 2.0, I get the error WindowsIdentity does not contain a definition for 'Impersonate'

Does anyone know how to fix this (or use an alternative that works as easily) for asp net core 2.0?

Any help is appreciated.

(Post is mainly code, adding text so I can submit question. /// )

Hybridism

Take a look at this. Core doesn't work with impersonation in the same way. learn.microsoft.com/en-us/aspnet/core/security/authentication/… – Publication

#46529621 – Lazare

Does this answer your question? .NET Core 2.1 Web API Impersonation causes WSALookupServiceEnd while processing error – Koeninger

https://mcmap.net/q/104519/-how-do-you-do-impersonation-in-net – Koeninger

Answer 1

Found a workable example:

// The following example demonstrates the use of the WindowsIdentity class to impersonate a user. 
// IMPORTANT NOTE: 
// This sample asks the user to enter a password on the console screen. 
// The password will be visible on the screen, because the console window 
// does not support masked input natively.


using System;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.Principal;
using Microsoft.Win32.SafeHandles;

public class ImpersonationDemo
{
    [DllImport("advapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
    public static extern bool LogonUser(String lpszUsername, String lpszDomain, String lpszPassword,
        int dwLogonType, int dwLogonProvider, out SafeAccessTokenHandle phToken);

    public static void Main()
    {
        // Get the user token for the specified user, domain, and password using the 
        // unmanaged LogonUser method. 
        // The local machine name can be used for the domain name to impersonate a user on this machine.
        Console.Write("Enter the name of the domain on which to log on: ");
        string domainName = Console.ReadLine();

        Console.Write("Enter the login of a user on {0} that you wish to impersonate: ", domainName);
        string userName = Console.ReadLine();

        Console.Write("Enter the password for {0}: ", userName);

        const int LOGON32_PROVIDER_DEFAULT = 0;
        //This parameter causes LogonUser to create a primary token. 
        const int LOGON32_LOGON_INTERACTIVE = 2;

        // Call LogonUser to obtain a handle to an access token. 
        SafeAccessTokenHandle safeAccessTokenHandle;
        bool returnValue = LogonUser(userName, domainName, Console.ReadLine(),
            LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT,
            out safeAccessTokenHandle);

        if (false == returnValue)
        {
            int ret = Marshal.GetLastWin32Error();
            Console.WriteLine("LogonUser failed with error code : {0}", ret);
            throw new System.ComponentModel.Win32Exception(ret);
        }

        Console.WriteLine("Did LogonUser Succeed? " + (returnValue ? "Yes" : "No"));
        // Check the identity.
        Console.WriteLine("Before impersonation: " + WindowsIdentity.GetCurrent().Name);

        // Note: if you want to run as unimpersonated, pass
        //       'SafeAccessTokenHandle.InvalidHandle' instead of variable 'safeAccessTokenHandle'
        WindowsIdentity.RunImpersonated(
            safeAccessTokenHandle,
            // User action
            () =>
            {
                // Check the identity.
                Console.WriteLine("During impersonation: " + WindowsIdentity.GetCurrent().Name);
            }
            );

        // Check the identity again.
        Console.WriteLine("After impersonation: " + WindowsIdentity.GetCurrent().Name);
    }
}

https://msdn.microsoft.com/en-us/library/dn906220(v=vs.110).aspx

Hybridism

Why not set the Console back- and foreground colors to the same color? – Circumlunar

Answer 2

.Net Core version 2.X not supporting Impersonating User. I tried multiple ways to implement the same but it doesn't return a safeHandle to execute.

UPDATE: Here's how to impersonate a user.

Cath

https://mcmap.net/q/1530195/-net-core-2-1-web-api-impersonation-causes-wsalookupserviceend-while-processing-error – Koeninger